豆浆乳酸菌发酵脱腥及在大豆冰淇淋中的应用研究

为了制备营养型大豆冰淇淋,本实验从自然发酵酸奶中分离纯化出六株乳酸菌,按照3%的量分别接种到调配好的豆浆中进行发酵。根据豆浆在发酵过程中pH的变化、菌株的发酵启动速度、产酸速率、凝乳时间和产品风味,筛选出优良的乳酸发酵菌株,再通过优良菌株互配发酵,获得组织状态好、无豆腥味的发酵豆浆,在大豆冰淇淋制作中应用,得到满意的效果。      

豆浆乳酸菌发酵脱腥及在大豆冰淇淋中的应用

为了制备营养型大豆冰淇淋,从自然发酵酸奶中分离纯化出6株乳酸菌,按照质量分数为3%的量分别接种于到调配好的豆浆中进行发酵.根据豆浆在发酵过程中pH值的变化,根据菌株的发酵启动速度、产酸速率、凝乳时间和产品风味,筛选出优良的乳酸发酵菌株,再通过优良菌株互配发酵,获得组织状好、无豆腥味的发酵豆浆,在大豆冰淇淋制作中应用,得到满意的效果.     

乳酸菌制剂对奶牛泌乳量及乳成分的影响

选择27头经产,产犊30～45d,产奶量相近,胎次相近,体重相近,健康无病的高产奶牛。随机分为3组,1组为基础对照组,2组（A组和B组）为试验组,试验组在基础日粮的水平上添加10g不同型号的乳酸菌制剂,预试期2周,正试期为6周。结果表明,两种乳酸菌对奶牛产奶量和奶成分有不同程度的影响,其中A组奶牛的产奶量比对照组有所增加,且差异显著（P〈0．05）,B组则有所下降;不同型号的乳酸菌制剂对牛乳成分也有不同程度的影响。A组奶牛除乳糖率与对照组相比有所降低外,其他乳成分（乳脂率、蛋白率和非脂固形物）相比对照组均有显著增长（P〈0．05）;B组奶牛其乳脂率呈上升趋势,日蛋白产量及日乳糖产量较对照组有所下降,对其他乳成分无显著影响。乳酸菌A能显著减少乳体细胞数（p〈0.05）。两种乳酸菌所生产牛奶的比重、冰点、酸度与对照组无显著差异。     

乳酸菌与酵母菌对牦牛酸乳品质形成的影响

为明确乳酸菌和酵母菌在牦牛酸乳品质形成中发挥的作用,以牦牛乳粉为原料、牦牛酸乳为发酵剂发酵酸乳,在发酵过程中分别抑制乳酸菌和酵母菌的活性,测定并比较正常发酵、抑制乳酸菌发酵、抑制酵母菌发酵酸乳的风味、口感、质构等相关指标。结果表明,乳酸菌和酵母菌对牦牛酸乳品质形成均起到关键作用,乳酸菌对酸乳酸度、质构、氨基酸态氮、有机酸、V_(B1)及酮类和酸类风味物质的贡献较大,酵母菌对乙醇、V_(B2)及醇类和酯类风味物质的贡献较大。     

菜谷系列乳酸发酵饮料菌种特性及质优菌种筛选研究

以3种蔬菜和4种谷物为原料,以5种不同来源的乳酸发酵菌种为基础,研究了不同菌种及其组合在所选定的单一蔬菜及混合蔬菜、单一谷物及混合谷物基质中的生长特性并以此为依据进行菌种筛选.研究结果表明:同等条件下不同菌种的差异是明显的,而利用这种菌种间和对发酵基质利用上的差异并加以科学整合将能为菜谷系列乳酸发酵饮料的研发提供较为现实和优化的菌种和原料基础.     

新疆自然发酵骆驼酸乳中乳酸菌降解胆固醇能力研究

以新疆骆驼酸奶分离出的10株初步鉴定为乳酸菌的菌株为研究对象,进行体外胆固醇降解能力的研究。用富集培养方法筛选出具有降解胆固醇能力的乳酸菌,然后将菌株接种到发酵培养基中进行发酵产酶,离心得酶液,用分光光度法测定其酶液对胆固醇的降解率,进而分析研究各菌株降解胆固醇的能力。有9株乳酸菌能够在以胆固醇为唯一碳源和能源的液体培养基中生长,其中3株菌对胆固醇降解率达到了60%。实验通过对自然发酵的骆驼酸乳中分离得到的乳酸菌的体外降解胆固醇的实验研究,表明骆驼酸乳中的乳酸菌具有一定的降解胆固醇的能力。     

大豆蛋白水解物促乳酸菌增殖发酵的研究

应用小型生物发酵罐对乳酸菌增殖作用进行发酵研究,结果表明,12g/100mL脱脂乳中添加大豆蛋白水解物增殖复合剂对嗜热链球菌和保加利亚乳杆菌生长具有显著的促进作用。添加酵母膏脱脂乳培养基的产酸量比脱脂乳增加1倍,添加增殖复合剂后为脱脂乳的3.12倍。添加增殖复合剂可使乳酸菌数量达到10个数量级,比脱脂乳培养基提高1～2个数量级。从累积添加碱量和单位加碱量两项指标来看,脱脂乳培养基乳酸菌生长呈现缓慢上升曲线,添加酵母膏呈现三段波浪式曲线,添加增殖复合剂为陡峭的上升曲线。单纯添加酵母膏不能支持乳酸菌连续生长,添加大豆蛋白水解物和酵母膏能够使乳酸菌生长快速启动,并维持一个较高生长水平,获得较大的细胞量的同时也充分利用乳中蛋白质。      

Influence of milk ultrafiltration on bacteriophages of lactic acid bacteria

Bacteriophages added to whole milk were partially concentrated during ultrafiltration. At 4:1 retentate, phage had concentrated 2.4:1. Thermal destruction at 54 degrees C followed first order kinetics up to 6% protein, whereafter it deviated. When allowed to grow in retentate in the presence of appropriate host, 3.5 generations of phage appeared after 12 h at 22 degrees C compared with four generations in skim milk. In the presence of phage, lactic acid bacteria population increased to only 10(7) cfu/ml compared with 3 X 10(9) in their absence. Retentate starter prepared in the presence of phage was as active as skim milk starter prepared in the presence of phage.     

母乳中乳酸菌的研究进展

母乳涵盖了婴儿成长所需的全部营养,为保证婴儿健康、快速生长,母乳喂养是最好的方式。传统培养技术和现代分子生物学技术已证明母乳是乳酸菌的天然来源,乳酸菌从母体肠道传递给乳腺的过程中免疫系统起到至关重要的作用。目前从健康母体的母乳中经常能够分离得到的乳酸菌有链球菌属(Streptococcus)、乳杆菌属(Lactobacillus)、乳球菌属(Lactococcus)、肠球菌属(Enterococcus)、双歧杆菌属(Bifidobacterium)、明串珠菌属(Leuconostoc)和片球菌属(Pediococcus)等。很多研究都已证明母乳中的乳酸菌具有特殊的功能如抑制病原微生物生长、免疫调节、调节肠道健康、抗HIV及治疗乳腺炎等。本文就母乳中乳酸菌的来源、母婴间乳酸菌的传递方式、母乳源乳酸菌的种类和功能特性等进行综述,以期为母乳源乳酸菌的开发和应用提供参考。      

长货架期饮用型酸奶的生产工艺

<正> 饮用型酸奶是一种低粘性的可饮用酸奶,无脂或含脂量极少,基本采用标准化牛奶作为原料,经热处理、均质并以酸奶发酵剂培养而成。 对于货架期要求只是2～3个星期的酸奶,一般只需进行均质和冷却处理,便已达到要求;要是所要求的货架期逾1个月以上,酸奶便要经过均质、巴氏杀菌和无菌灌装处理。发酵后的酸奶如要进行巴氏杀菌或高温灭菌,可添     

乳酸菌在酱油酿造工业及蔬菜加工中的应用

该文扼要地介绍了乳酸菌的分类、生理特性和保藏方法，较详细地介绍了乳酸菌在酱油酿造、蔬菜加工中的应用概况。指出了乳酸菌参与酱油酿造有不同程度的增香效果；应用于蔬菜加工中，不仅改善了产品的风味，而且提高了营养价值。     

Effects of ultrasound on the fermentation profile of fermented milk products incorporated with lactic acid bacteria

Ultrasonic processing of fermented milk products has created much interest in current research on dairy products. This has been employed in cultured milk products to enhance the emulsification of milk fat and to intensify the fermentation process. Benefits including remarkable product stability, reduced processing time and enhanced quality are being recorded. Ultrasound (US) altered the colour and flavour profile of milk; however, the effect of US-induced fermentation on the synthesis of flavour compounds in milk has not been reported in the literature. This review paper presents a comprehensive scenario on the impact of power US on the fermentation profile and quality of ultrasonically processed dairy products. A theoretical background on US and details of its effect on the metabolic performance of lactic acid bacteria are presented. Finally, it describes how the quality attributes of fermented milk gels are modified due to the intensification of the fermentation process with US.     

Effects of lactic acid concentration and spray drying conditions on stickiness of acidified skim milk powder

The effects of lactic acid concentration (LA) and spray drying conditions on stickiness of acidified skim milk powder (SMP), which impacts process efficiency and powder properties, were examined using a fully replicated 2^4-1 fractional factorial design. The wall deposition was significantly affected by LA, and yield was positively influenced by the drying temperature difference. Drying temperature difference significantly affected particle size, moisture content and water activity of acidified SMP. Particle size was also significantly influenced by nozzle airflow rate. Moisture content and water activity were significantly affected by LA, while glass transition temperature was only influenced by the outlet temperature.     

乳酸菌饮料中乳酸菌微生物学检验技术的分析与探讨

只有活性乳酸菌群≥10^6个／mL的乳酸菌饮料，才能真正起到增强机体免疫功能、延缓机体衰老等保健作用，检测活性乳酸菌的含量成为判断产品质量好坏的重要手段。该文通过大量试验，对国标中乳酸菌检验方法中菌落特征及菌体形态的文字描述作了进一步细化、具体化的实物图像补充，从抽象的文字描述转变成更清晰、形象的图像说明，为准确计数乳酸菌总数提供了依据。     

Effects of dietary deoiled soy lecithin supplementation on milk production and fatty acid digestibility in Holstein dairy cows

Deoiled soy lecithin is a feed additive enriched in phospholipids. Our study evaluated the effects of dietary deoiled soy lecithin supplementation on (1) milk production and composition, (2) plasma and milk fatty acid (FA) content and yield, and (3) apparent FA digestibility and absorption in lactating dairy cows fed fractionated palm fat. In a split-plot Latin square design, 16 Holstein cows (160 ± 7 days in milk; 3.6 ± 1.2 parity) were randomly allocated to a main plot receiving a corn silage and alfalfa haylage-based diet with palm fat containing either moderate (MPA) or high palmitic acid (HPA) content at 1.75% of ration dry matter (72 or 99% palmitic acid, respectively; n = 8/palm fat diet). On each palm fat diet, deoiled soy lecithin was top-dressed at 0, 0.12, 0.24, or 0.36% of ration dry matter in a replicated 4 × 4 Latin square design. Following a 14-d covariate period, lecithin supplementation spanned 14 d, with milk and blood collected during the final 3 d. Milk composition and pooled plasma markers were measured. The statistical model included the fixed effects of palm fat type, lecithin dose, period, and the interaction between palm fat type and lecithin dose. The random effect of cow nested within palm fat group was also included. Lecithin linearly decreased dry matter intake. In cows fed HPA, lecithin feeding reduced milk fat content and tended to decrease milk fat yield. Although no changes in milk yield were observed, a quadratic reduction in 3.5% fat-corrected milk was observed with increasing lecithin dose. Lecithin linearly increased energy-corrected milk efficiency in cows fed MPA. Lecithin supplementation also decreased milk urea nitrogen, relative to unsupplemented cows. The proportion of 16-carbon FA in milk fat decreased linearly with lecithin dose, whereas 18-carbon FA increased linearly. Lecithin reduced de novo FA (<16-carbon) content and tended to increase preformed FA (>16-carbon) content in a linear manner. Compared with MPA, HPA diets reduced apparent total and 16-carbon FA digestibility and absorption. Deoiled soy lecithin feeding did not modify FA digestibility or absorption. Our observations suggest that soy lecithin feeding modifies rumen digestion to reduce dry matter intake and change milk composition.     

乳酸菌发酵香蕉酸奶的研究

本研究是将香蕉制汁后和牛奶混合,将嗜热链球菌及保加利亚乳杆菌以１∶１混合作为发酵剂进行乳酸发酵,用Ｌ９（３~４）正交试验得出最佳配料组合,研制出了具有浓郁香蕉风味的乳酸菌发酵酸奶。     

酱油发酵过程中的耐盐乳酸菌筛选及对低盐固态酱油品质的影响

本文通过对酱醪中耐盐乳酸菌的筛选,成功分离出一株耐18%盐度的乳酸菌,经过16S r DNA测序鉴定,确定为一株植物乳杆菌。在酱油酿造过程中添加该耐盐植物乳杆菌,无盐固形物、氨基酸态氮、还原糖和总酸含量等理化指标都有所上升。经过液相测定,发现酱油中乳酸含量比空白增加2倍左右。挥发性风味物质中酮类和酚类物质增加2倍左右,醇类物质稍有增加。本研究为进一步安全有效提高酱油风味物质奠定理论依据。      

大豆干热预处理对豆浆品质的影响

为研究干热预处理大豆对豆浆的影响,采用干热方法对大豆进行预处理后制备豆浆,研究干热对豆浆表面微观结构,豆浆得率、可溶性固形物含量、蛋白含量、脲酶、胰蛋白酶抑制因子、粒径和感官品质的影响。结果表明:与常规法相比,干热预处理对豆浆微观结构的影响较大,显著降低脲酶、胰蛋白酶抑制因子的活性,其蛋白含量较多。常规法制浆在豆浆得率、可溶性固形物、粒径和感官评分方面优于干法制浆。     

Suppression of the melanogenesis and cellular antioxidant activity in B16 melanoma cells

The results of antioxidant activities by ORAC assay and CAA assay were evaluated for melanogenesis. Although the antioxidant activity by ORAC was not correlated with the melanogenesis, the samples which showed high antioxidant activity by CAA tended to suppress melanogenesis. Caffeic acid and Citrus depressa juice, which demonstrated inhibitory effects on mela‐nogenesis, had high antioxidant activities but no inhibitory effects on tyrosinase activity. In addition, they inhibited the melanogenesis which was increased by inhibition of catalase activity. These results may suggest that antioxidant activity by CAA can contribute to the suppression of melanogenesis in B16 melanoma.